178 PHOTOGRAPHY IN ASTRONOMICAL RESEARCH. 



produced by TNIessrs. IJopsold, with the astonishino- result that tlie 

 troubles from personal ('(juatiou. which have so loui>- been a difficulty 

 in all fundamental work. ha\(' pi'actically disa})j)eared. 



This bi>autiful invention has placed the I've onCe more in a position 

 actually superior to the i)hot()i>'raphic j)late. for with the eye Ave can 

 observe stars in dayliaht. and so- secure information of great impor- 

 tance, whereas no photogi'aphic method of doing this has as yet been 

 devised. And there is also the fact that for faint stars a long 

 exposure would be re(iuired for what the eye can accomplish in a few 

 seconds. 



Thus in one oi* two astronomic chamiels the effects of the rising 

 tide of photography have scarcely yet been felt; but into all the others 

 it has swept Avith ever-groAving force. Looking back over the thirty 

 years of adA^ance, Ave may be well satisfied. ^Vith more funds, and 

 especially Avith more men, no doubt moi-e could have been done; let 

 us eA'en admit that we might have done better Avith the same funds 

 and the same limited staff. But on the Avhole Ave liaA'e been fortunate. 

 At a critical time, when Ave mighfhave felt the want of larger endoAv- 

 ments acutely, the need was almost anticipated by a stream of bene- 

 faction. If tliis stream had its chief source in the United States, its 

 beneficial effects have poured over the Avhole world, and induced cur- 

 rents haA^e begun to floAv elseAvhere. We uiay reflect Avith thankful- 

 ness hoAV nuTch harder our adA'ance might have been but for the noble 

 gifts to the Harvard, the Lick, and the Yerkes observatories, and 

 earnestly hope that the cheerful expectations of a great American 

 astronomer, that these are but the foreshadoAving of much larger gifts 

 to science, may be adequately realized. 



May I noAv turn to one or tAvo of the problems Avith which this new 

 deA^elopment of our Avork has brought us face to face? They are 

 numerous and serious, and it is impossible to consider many of them, 

 perhaps even the most important of them. One of the most pressing 

 is the problem of rendering generally accessible the vast accumula- 

 tions of material for study that have been suddenly thrust up(m our 

 attention. Hoav aiv our photographs to be stored, preserved, and 

 published? Even now troubles have gathered, and time Avill only 

 multiply them. It is nuiny years since Professor Pickering drew 

 attention to the difficulties in storing the ])hotographic plates taken 

 at the Harvard Observatory. When many thousands of photographs 

 haA'e been accumulated, not only the s])ace they occupy, but the actual 

 Aveight of glass is an embarrassment. And there seems to be no doubt 

 concerning the duty of accumulation. May I confess an early and 

 mistaken view Avhich 1 formulated on this nuitter? T reasoned thus: 

 The proper moment for making use of a jjhotograph taken last night 

 is to-day. It is useless to defer the examination until to-moi'i'ow, for 

 there Avill then be new jihotographs claiming attention. Hence it is 



